On Wed, Mar 31, 2010 at 3:51 PM, Heinrich Apfelmus
which were introduced by John Hughes in his Phd thesis from 1983. They are intriguing! Unfortunately, I haven't been able to procure a copy of Hughes' thesis, either electronic or in paper. :( Can anyone help? Are there any other resources about this parallel approach?
Aye, returning lazy pairs is one of those things that seems rather magical in several respects. Out of curiousity, have you looked at the unsafePerformIO thought experiment near the end of my Monad Reader article? It demonstrates that returning lazy pairs can introduce multiple code paths through a single function, reminiscent of (but different than) multi-mode logical relations. (Mercury, for example, optimizes relations differently depending on their mode.) I too am interested in looking at Hughes' thesis, I tried tracking it down early last year with little success. Best, Leon